This invention relates generally to control and monitoring systems, and more particularly to microprocessor based controllers and monitoring systems.
Engine-generator sets are used to provide an on-site alternate source of electrical energy in hospitals, offices, data centers, factories, institutions, hotels and other buildings where an interruption to the utility source of power may cause unsafe situations or which may result in economic loss. In addition, engine-generator sets may be used to provide electrical energy in remote areas where there is no utility power available. Engine-generator sets may also be used as a distributed source of electrical energy, to reduce the peak load on utility electrical generation systems during peak electrical demand periods, for example, during the summer.
Typically, the engine-generator set is sent a signal to start automatically by an engine-generator control system, without manual intervention, for example upon loss of utility power or at the beginning of a peak demand period. When the engine-generator set develops an abnormal operating condition or malfunction during operation, or when the power generated by the engine-generator set is no longer required, for example upon restoration of utility power or at the end of the peak demand period, the engine-generator set is sent a signal to shutdown by an engine-generator control system.
Known engine-generator controllers use microprocessors to control the operation of an engine-generator set and in some cases provide or have interfaces to annunciation equipment, such as incandescent lights or light emitting diodes to display the status and operating condition of the engine-generator. Those known engine-generator controllers have fixed input/output capabilities and control and monitor the engine-generator using hard-wired discrete control wiring. Thus, known engine-generator controllers are unable to monitor or display the actual operational parameters of the engine-generator, oil pressure or oil temperature for example.
It is difficult to expand the input/output capabilities of known engine-generator controllers without the use of special hardware and custom programming. In addition, known engine generator controllers are unable to operate over a range of input control voltages and have no network communication capabilities. Also, known engine-generator controllers are unable to display the power quality of electrical energy generated by the engine-generator. In addition, known engine-generator controllers lack a real-time clock and data storage and retrieval system and are therefore unable to log the operational status of the engine-generator set.
Therefore, it would be desirable to provide an integrated controller which can be configured and expanded to match unique requirements for an on-site installation, without the need for special hardware or custom programming.
It is also desirable to provide a controller with communication capabilities for direct communications with a control system and for providing monitoring capabilities so that the operational status of the controller and the system controlled can be closely monitored, and where communication protocols of the controller are easily changed by substitution of communications circuit cards.
In addition it would be desirable to provide a real-time clock, and a data storage and retrieval system so that the operational data from the controller may be retrieved using a wired or wireless communication system.
Finally, it would be desirable to provide a web-enabled controller so that operational data can be accessed, retrieved, and controlled through the Internet.
The invention includes a microprocessor based engine generator controller that controls the starting and stopping of an engine-generator set, and provides the capability to view the status of the controller and engine-generator, in a stand alone configuration or as part of a web-based application. The method for such control includes configuring the engine-generator controller for the control application, monitoring parameters of the engine-generator controller, monitoring operational status of the system under control of the engine-generator controller, and storing a status of the engine-generator under control of the controller. Further, the controller communicates with the engine-generator over a communications bus, which allows the controller to display the actual values of the operating parameters of the engine-generator under control.